[Behavioral disorders in Parkinson's disease: from pathophysiology to the mastery of dopaminergic treatment]

INTRODUCTION

Behavioral changes in Parkinson's disease are complex and their pathophysiology is not yet fully understood. The dopaminergic system seems to play a major role and most of the behavioral disorders in Parkinson's disease can be classified into either hypodopaminergic if related to the disease itself or hyperdopaminergic if related to dopaminergic treatment.

STATE OF THE ART

Subthalamic stimulation, which enables withdrawal of dopaminergic medication at an advanced stage in the disease, provides a model for the study of certain nonmotor, dopamine-sensitive symptoms. Such a study has shown that apathy, which is the most frequent behavioral problem in Parkinson's disease, is part of a much broader hypodopaminergic behavioral syndrome which also includes anxiety and depression. Nonmotor fluctuations--essential fluctuations in the patient's psychological state--are an expression of mesolimbic denervation, as shown in positron emission tomography. Drug-induced sensitization of the denervated mesolimbic system accounts for hyperdopaminergic behavioral problems that encompass impulse control disorders that can be alternatively classified as behavioral addictions. The association of impulse control disorders and addiction to the dopaminergic medication has been called dopamine dysregulation syndrome. While L-dopa is the most effective treatment for motor symptoms, dopamine agonists are more effective in improving the nonmotor levodopa-sensitive symptoms. On the other hand, L-dopa induces more motor complications and dopamine agonist more behavioral side effects. There is increasing data and awareness that patients' quality of life appears to be dictated by hypo- and hyperdopaminergic psychological symptoms stemming from mesolimbic denervation and dopaminergic treatment rather than by motor symptoms and motor complications related to nigrostriatal denervation and dopaminergic treatment.

PERSPECTIVES

Better management requires knowledge of the clinical syndromes of hyper- and hypodopaminergic behaviors and nonmotor fluctuations, a better understanding of their underlying mechanisms and the development of new evaluation tools for these nonmotor symptoms.

CONCLUSIONS

The neurologist who strives to gain mastery of dopaminergic treatment needs to fine tune the dosage of levodopa and dopamine agonists on an individual basis, depending on the presence of motor and nonmotor signs respectively.

Bowman-Birk inhibitor affects pathways associated with energy metabolism in Drosophila melanogaster

Bowman-Birk inhibitor (BBI) is toxic when fed to certain insects, including the fruit fly, Drosophila melanogaster. Dietary BBI has been demonstrated to slow growth and increase insect mortality by inhibiting the digestive enzymes trypsin and chymotrypsin, resulting in a reduced supply of amino acids. In mammals, BBI influences cellular energy metabolism. Therefore, we tested the hypothesis that dietary BBI affects energy-associated pathways in the D. melanogaster midgut. Through microarray and metabolomic analyses, we show that dietary BBI affects energy utilization pathways in the midgut cells of D. melanogaster. In addition, ultrastructure studies indicate that microvilli are significantly shortened in BBI-fed larvae. These data provide further insights into the complex cellular response of insects to dietary protease inhibitors.

Systematic review: the costs of ulcerative colitis in Western countries

BACKGROUND

Early onset and complications such as hospitalization and surgery contribute to the economic burden of ulcerative colitis.

AIM

To review systematically the literature on costs of ulcerative colitis in Western countries.

METHODS

Studies estimating costs of ulcerative colitis in Western countries were identified using Medline, EMBASE and ISI Web of Science and were rated based on relevance and reliability of estimates. All costs were adjusted to 2008 currency values. A parallel review focused on the impact of disease severity on costs, hospitalizations and surgeries.

RESULTS

Estimated annual per-patient direct medical costs of ulcerative colitis ranged from $6217 to $11,477 in the United States and from euro8949 to euro10,395 in Europe. Hospitalizations accounted for 41-55% of direct medical costs. Indirect costs accounted for approximately one-third of total costs in the United States and 54-68% in Europe. Total economic burden of ulcerative colitis was estimated at $8.1-14.9 billion annually in the United States and at euro12.5-29.1 billion in Europe; total direct costs were $3.4-8.6 billion in the United States and euro5.4-12.6 billion in Europe. Direct costs, hospitalizations and surgeries increased with worsening disease severity.

CONCLUSIONS

Ulcerative colitis is a costly disease. Hospitalizations contribute significantly to direct medical costs, and indirect costs are considerable, having previously been substantially underestimated.

Laetispicine, an amide alkaloid from Piper laetispicum, presents antidepressant and antinociceptive effects in mice

In the present work, we studied the effect of laetispicine, an amide alkaloid isolated from the stems of Piper laetispicum (Piperaceae), in forced swimming, open field, acetic acid writhing and formalin tests in KM mice to assess antidepressant and antinociceptive effects. A significant and dose-dependent decrease in the immobility time, as evaluated by the forced swimming test, was observed after laetispicine administration (38.18, 39.79, 58.77 and 67.28% decreased at the doses of 5, 10, 20, 40mg/kg, respectively), suggesting an antidepressant effect. Furthermore, in the open field test, laetispicine at the given doses did not alter the number of crossings and rearing, as compared to controls. Results from writhing and formalin tests showed that laetispicine reduced the number of writhing in mice in a dose-dependent manner, attenuated the licking and spiting time of the injected paw in the first phase of formalin test. The antinociceptive effect of laetispicine was not affected by pre-treatment (i.p.) with naloxone (2mg/kg). In conclusion, we showed that laetispicine possessed significant antidepressant and antinociceptive properties, making this drug potentially useful in depression and pain.

Iron oxide nanoparticle platform for biomedical applications

Progress in nanosynthesis has succeeded in making nanoscale particles from iron oxide under precise quality control. Given the recent great advances in polymer manufacturing, antibody purification, DNA/RNA synthesis and magnetic resonance imaging (MRI), such iron oxide nanoparticles (IONPs) have been enriched with many variables and attracted great interest in studying their potential biomedical applications. After nearly two decades' effort, IONPs have become a powerful platform in many diverse aspects of biomedicine, including MRI, gene and drug delivery, and hyperthermia. While some studies are still at the proof-of-concept stage, others have now been widely used in clinics. With the on-going efforts to enhance their targeting ability and endow more functions, IONPs' future applications are highly expected.

Genome-wide identification of quantitative trait loci for carcass composition and meat quality in a large-scale White Duroc x Chinese Erhualian resource population

Carcass and meat quality traits are economically important in pigs. In this study, 17 carcass composition traits and 23 meat quality traits were recorded in 1028 F(2) animals from a White Duroc x Erhualian resource population. All pigs in this experimental population were genotyped for 194 informative markers covering the entire porcine genome. Seventy-seven genome-wide significant quantitative trait loci (QTL) for carcass traits and 68 for meat quality were mapped to 34 genomic regions. These results not only confirmed many previously reported QTL but also revealed novel regions associated with the measured traits. For carcass traits, the most prominent QTL was identified for carcass length and head weight at 57 cM on SSC7, which explained up to 50% of the phenotypic variance and had a 95% confidence interval of only 3 cM. Moreover, QTL for kidney and spleen weight and lengths of cervical vertebrae were reported for the first time in pigs. For meat quality traits, two significant QTL on SSC5 and X were identified for both intramuscular fat content and marbling score in the longissimus muscle, while three significant QTL on SSC1 and SSC9 were found exclusively for IMF. Both LM and the semimembranous muscle showed common QTL for colour score on SSC4, 5, 7, 8, 13 and X and discordant QTL on other chromosomes. White Duroc alleles at a majority of QTL detected were favourable for carcass composition, while favourable QTL alleles for meat quality originated from both White Duroc and Erhualian.

Quantitative detection of cytokeratin 20 mRNA in urine samples as diagnostic tools for bladder cancer by real-time PCR

AIM

To determine and compare cytokeratin 20 (CK20) mRNA expression in urine of patients with transitional cell carcinomas of bladder (TCCB), urological benign diseases, and healthy volunteers.

METHODS

Taqman probe was designed according to the sequence of CK20 cloned gene. The quantitative PCR reaction system was optimized and evaluated. The CK20 mRNA level was screened by real-time polymerase chain reaction (RT-PCR) in 95 urine samples and analyzed according to the following parameters: urinary cytology, nuclear matrix protein 22 (NMP22) expression, tumor stage and grade.

RESULTS

For 60 TCCB patients urinary cytology was positive in 28 (46.7%), control group had no false-positive results (specificity 100%). CK20 expression was positive in RT-PCR of 51 cases (85%) of TCCB, but control group was positive in 2 cases (specificity 94.3%) with a cutoff value of crossover point (CT) = 30. Two methods have significant variation in sensitivity (p < 0.001), NMP22 expression was positive in 47 cases (78.3%), but control group was positive in 9 cases (specificity 85%). In the simultaneous evaluation of CK20 and NMP22 mRNA expression, there were 54 positive cases (90%). CK20 mRNA values in TCCB group (mean 27712.57 copies/microl) were significantly higher than in non-cancer disease urological group (mean 74.45 copies/microl) and control group (mean 8.47 copies/microl) (p < 0.001, p < 0.001, respectively). CK20 mRNA values increased gradually with higher tumor grade and stage: G1 differs significantly from G2 (p = 0.016); T(is) /T(a) differs significantly from T(1-2) (p = 0.022).

CONCLUSION

Our results indicate that CK20 mRNA expression could be regarded as a potential marker for TCCB. We demonstrated correlation between CK20 expression and the clinicopathologic features of TCCB (tumor stage and grade); simultaneous use of CK20 and NMP22 markers will elevate the sensitivity of the method. CK20 RT-PCR is a sensitive, quantitative, rapid and specific method to detect free cancer cells in the urine, and could be recommended for be wide application in the diagnostics of TCCB and evaluation of therapeutic effect.

Establishment of an experimental intracranial internal carotid artery model and the application in covered-stent navigability testing

BACKGROUND AND PURPOSE

The carotid siphon is a natural barrier to intracranial interventions. Our aim was to make a model of the human intracranial internal carotid artery (ICA) and to test the navigability of covered stents for intracranial applications.

MATERIALS AND METHODS

A digital tube was made on the basis of raw MR images of the human ICA. It was transferred into 10 physical models and then coated with silicone by using a 3D rapid prototyping (RP) machine. Ten dogs then underwent surgery. Their common carotid arteries (CCAs) were exposed, cut, and passed through 1 of the tubes. Finally, the vascular models were made by reanastomosis of their CCAs. Eight expended polytetrafluoroethylene (e-PTFE) covered stents (two 3.5 x 16 mm, two 3.5 x 13 mm, two 3.5 x 10 mm, and two 3.5 x 7 mm) were implanted 1 week later. Two dogs remained as controls. The performance of the device was evaluated by angiography and histopathologic examination.

RESULTS

Ten animal models were successfully constructed. There was no vascular spasm or thrombosis when assessed by angiography. Destruction of the tunica intima and media was found in the 3.5 x 16 mm stent group. Destruction of the endothelium was found in the 3.5 x 13 mm stent group, and only flattening of the endothelium was found in the 3.5 x 10 mm and 3.5 x 7 mm stent groups.

CONCLUSIONS

The experimental model was thought to simulate adequately the geometry of the human ICA and, thus, would be an effective tool for the research and testing of neurovascular devices. The length of the stent is 1 factor influencing the navigability in tortuous vessels.

Transcriptional signatures in response to wheat germ agglutinin and starvation in Drosophila melanogaster larval midgut

One function of plant lectins such as wheat germ agglutinin is to serve as defences against herbivorous insects. The midgut is one critical site affected by dietary lectins. We observed marked cellular, structural and gene expression changes in the midguts of Drosophila melanogaster third instar larvae that were fed wheat germ agglutinin. Some of these changes were similar to those observed in the midguts of starved D. melanogaster. Dietary wheat germ agglutinin caused shortening, branching, swelling, distortion and in some cases disintegration of the midgut microvilli. Starvation was accompanied primarily by shortening of the microvilli. Microarray analyses revealed that dietary wheat germ agglutinin evoked differential expression of 61 transcripts; seven of these were also differentially expressed in starved D. melanogaster. The differentially transcribed gene clusters in wheat germ agglutinin-fed larvae were associated with (1) cytoskeleton organization; (2) digestive enzymes; (3) detoxification reactions; and (4) energy metabolism. Four possible transcription factor binding motifs were associated with the differentially expressed genes. One of these exhibited substantial similarity to MyoD, a transcription factor binding motif associated with cellular structures in mammals. These results are consistent with the hypothesis that wheat germ agglutinin caused a starvation-like effect and structural changes of midgut cells of D. melanogaster third-instar larvae.